Enhancing Pt electrocatalytic activity by surface functionalization of carbon s...

• Author(s): Capelo, Anabela ; Esteves, M. Alexandra ; Sá, A. I. Correia de ; Rangel, C. M.
• Date: 2013
• Persistent ID: http://hdl.handle.net/10400.9/2000
• Origin: Repositório do LNEG
• Subject(s): Pt electrocatalysts; Chemically modified carbon; Sulphonic groups; Methanol Oxidation; Pt Dissolution; Chloride solutions
• Document Type: Conference Object
• Language: English

Description

Preliminary results are presented for Pt deposited on 4-aminobenzenesulphonic acid-functionalized carbon, Pt/C_ABSA. Vulcan XC-72R was functionalized with the objective of influencing the dispersion of catalyst nanoparticles and to decrease the resistance of three phase boundaries, by introducing sulphonic groups. Electrochemical characterization of the supported catalyst was done in a 0.5 M sulphuric acid solution with added chloride and also using methanol demonstrating well defined features and stable voltammograms after 30 cycles, with apparent higher currents when compared with commercial catalyst. The structure sensitive adsorption of anions on platinum is confirmed by the blocking effect of chloride ions in the hydrogen adsorption-desorption region as well as by the consequent dissolution of platinum, evident in both anodic and cathodic features of the voltammograms regarding surface oxide formation and reduction. The partial reversibility of the effect of chloride ions is discussed. Research is in progress in order to accomplish a comprenhensive characterization of the synthesized catalyst and to ascertain the effect of the sulphonic groups.